Method of treating photographic film.



J. l. CRABTREE.

METHOD or TREATING PHoToGnAPHlc FILM.

APPLICATION FILED MAY l1, |914.l

Patented Jan. 18, 1916.

2 SHEETS-SHEET l.

Patented Jan. 18, 1916.

1. l. cRAmEE. METHOD 0F TREATING PHOTOGRAPHIC FILM.

APPLICATION FILED MAY ll 1,168,286.

' 2 SHEETS-SHEET 2.

John Ickerzyz'il Cra tree .UNITED sTATEs PATENT oEErcE.

JOHN ICKERINGILL CRABTREE, OF ROCHESTER, NEW YORK, ASSIGNOR T0 EASTMAN KODAK COMPANY, ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

METHOD OF TREATING PHOTOGRAPHIC FILM.

A Specification of Letters Patent.

Patented J an. 18, 1916.

Application led May 11, 1914. Serial N' o. 837,961.

T0 all wh-0m it may concern:

Be it known that I, JOHN ICKERINGILL CRABTREE, of Rochester, in the county of Monroeand State of New York, have invented certain ynew and usefgi Improvements in Methods of Treating Photographic Film; and` I dorhereby declare thev following to be a full, clear, and exact description of the same, reference being had .to the accompanying drawings, ,forming a part of this specification, and to `thejre'ferencenumerals marked thereon. r

My present invention-relates to photography and more particularly y*to iexible photographic film, and ithaslfor its object to provide an improvedand efficient method of protecting one side of 'av film' when it is desired `to make a liquidvor other applicati'onto the .other side exclusively. y

A further object of the invention is to provide for thetreatment in the lmanner indi! cated of long strips of film, such as motion picture strips the improvements being particularly applicable when it iis desired to dye the Vtwo faces separately so that,l they may present a combination of color values to transmitted light.

To these and other ends the invention con# sists in certain improvements and combinationsv of parts all as will be hereinafter more fully `described, the novel features bef ing pointed out in the claims atv the end of the specification. In the drawings: Figure lis a front elevation ofone type of mechanical apparatus adapted. for use in treating photographic iilm in accordance with my lnvention; Fig.

2 is a transverse section thereof, taken'sub stantially on the line 2--2 of Fig. 1;'Fig. 3 is an enlargedy fragmentary, sectional vlew taken substantially on the line 3-3 of Fig.

' 1, and Fig. 4 is an enlarged longitudinal central section taken substantiallyA on the line y en 'of rig.l 2. f

Similar reference numerals in the .several figures indicate the same parts.

The specific apparatus shown in the drawi ings formsno part of the subject matter. to.

be claimed lin this application, the right be'- ing reserved to claim these mechanical. features in a separate d1v1s1onal apphcationY to be hereinafter filed. An explanation'` of such apparatus will, however, aid in obtain- 'ing an understanding ofthe general me constituting the present invention.

In this view, and referring more particularly to the drawings, A indicates, generally, a preferably semi-cylindrical tank or convtainer in the end standards 1 of which is journaled at 2 a hollow shaft B, carrying a vdrum C. Continuationsof thelstandards 1 constltute supporting legs 3 for the tank,

interior with suitable openings 5 for theflow of compressed air admitted from a pipe 6 through a check'valve 7 at one of the projecting ends 8- of the shaft. The pipe 6 may represent any suitably controlled source of .fluid pressure supply.

The framework of the drum C is, in the i present instance, comprised by imperforate circular heads 9 on the peripheries of which are secured the endsof slats 10. It is the intention that fluid be permitted to escape or to communicateits pressure through or past these slats for which purposethe may v be perforated at intervals, but l pre 'er, as shown in the present instance, to form narrow slots or passages 11 between them byI spacing them slightly from each other, as shown. This slotted periphery is completely vcovered by a continuous sheet of soft, elastic and non-absorbent material 12'such as dental rubber. The covering lies loosely upon the periphery and is secured only at the ends where'the margins 13 of the cylindrical sheet are clamped by means of plates 14 and screws`15 to the heads 9.

It will thus be seen that when air or other Huid under pressure is admitted to the interior of the drum through the pipe Gand hollow shaft' B, the covering 1 2 will be inated and will swell out beyond contact with the frame of the drum. It is-so shown in `F ig. ,4: while in"'Fig. 2 it is shown before inflation where it hugs the drum frame. In order to prevent the thin rubber from blowing .out or becoming loosened'or undulyV distended at the vends, I cement it at these points to a canvas or other inextensible band v16 which may or may not be in' turn ce- Y to the slats 10. There is therefore 5a non-inflatable marginal surface at each edge of; the cylinder' which performs the function stated for a purpose that will here- 110 of treating motion picture strips for the projection of'pictures in color, it is desired to dye one side of the strip exclusively red and the other side exclusively green. In the practice of my present invention in connection with the particular apparatus just described, I Wind the strip, indicated at D,

spirally upon the drum C, as shown in Fig. 1, with the proximate edges of adjacent convolutions slightly separated, the covering 12 being deflated at the time by reason of an absence of pressure in the interior of the drum. One end of the film may have attached thereto a yoke 18 that is initially engaged over a hook 19 on the drum to anchor it and at thel completion of the Winding the other end may be fastened down with a strip of adhesive tape 20 to prevent unwinding or slippage in the convolutions, or other means may be employed at both ends for like purposes. Air or other fluid pressure is then admitted to the interior of the drum in the manner described, and to a reasonable extent. The immediate result is that the covering 12 becomes inflated and forces its fiuid tight, clinging surface securely against the under surfaces of the film convolutions, bulging forth slightly between the latter to lock 0H the entrance of fluid in a definite manner at the edges. The dye is then placed in the tank A. to such a depth as to partially submerge the drum and the latter rotated by means of a crank 21, or otherwise, carrying every portion of the periphery and hence of the strip D to immersion in the dye, the outer surface only being exposed thereto. The film may be dried while still on the drum` With the latter inflated and then removed, reapplied in a reverse position With the dyed surface protected and the clear surface exposed'and the operation repeated with the other dye, the drum of course being deflated previous to the rewinding.

Of course there is bound to be ineffective protection to the extreme ends of the strips and it is therefore preferable to attach leaders carrying the fastening devices 18 and 2O to the film body to be treated at each end. These may be composed of short pieces of spoiled film or other material of corresponding size temporarily joined up to. the film body by adhesive tape, for instance. These leaders will thereby form the first one or two convolutions and constitute the portion of the whole strip that rest upon the ineXpansible end bands 16.

I claim as my invention:

1. The method of protecting one side of a photographic film from an application made to the other side Which consists in confining the side to be protected against an inflated surface While such application is being made.

2. The method of protecting one side of a photographic film from an application made to the other side, Which consists in confining the side to be protected against the surface of an inflatable body, inflating said body and then making the application to the other side.

3. The method of protecting one side of a photographic film strip from an application made to the other side, Which consists in Winding the strip about an inflatable body with the side to be protected confined against the surface of the body, inflating said body and then making the application to the other side of the film strip.

4. The method of protecting one side of a photographic film strip from an application made to the other side, which consists in Winding the strip in spiral convolutions about an inflatable body with the side to be protected confined against the surface of the body and the ends of the strip secured, infiatin said body and then making the application to the other side of the strip.

5. The method of applying a liquid treatment to one side only of a photographic film strip, which consists in Winding the strip about an inflatable body, infiating said body and then immersino' the surface of said body l:'nlflthe strip carrled thereon in the liquid 6. The method of protecting one side of a photographic film from an application made to the other side which consists in confining the side to be protected against a pneumatically inflated rubber surface While such application is being made.

JOHN ICKERINGILL CRABTREE. 

